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Voltage-coupled conformational dynamics of mitochondrial protein-import channel

Mitochondria contain multisubunit translocases to import preproteins from the cytosol. The presequence translocase of the inner membrane operates in a voltage-gated manner, but how a preprotein-conducting channel responds to the membrane potential was unknown. A new study identifies a voltage-coupled conformational change in a transmembrane segment of the Tim23 import channel, representing a major step toward understanding the molecular basis of a voltage-gated protein translocase.

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Figure 1: The mitochondrial machinery for import of preproteins with positively charged presequences.
Figure 2: Molecular mechanism of the presequence translocase of the inner mitochondrial membrane (hypothetical model).


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We thank M. Bohnert and C. Mehnert for discussion. This work was supported by the Deutsche Forschungsgemeinschaft, Sonderforschungsbereich 746 and the Excellence Initiative of the German Federal and State Governments (EXC 294 BIOSS).

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Correspondence to Martin van der Laan or Nikolaus Pfanner.

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van der Laan, M., Schrempp, S. & Pfanner, N. Voltage-coupled conformational dynamics of mitochondrial protein-import channel. Nat Struct Mol Biol 20, 915–917 (2013).

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